Saeki Y, Tada K, Sano T, Takahashi Y
Department of Pharmacy, Japanese Red Cross Medical Centre, Tokyo, Japan.
Biopharm Drug Dispos. 1996 Jan;17(1):71-9. doi: 10.1002/(SICI)1099-081X(199601)17:1<71::AID-BDD937>3.0.CO;2-C.
A kinetics model is proposed for platelet disposition after transfusion of platelets. In this model, transfusion of platelets and production of endogenous platelets contribute to an increase in the number of platelets in patients, and the life span and age of each platelet contribute to a decrease. The time course of the number of platelets after transfusion of platelets is theoretically described by this model to be a straight line followed by a concave curve. When the platelets have a life span without any variation, a linear pattern is observed in spite of their different ages at the transfusion. This model with a constant life span was applied to three patients receiving platelet transfusion, and the model parameters were calculated by curve fitting the observed platelet levels to the model using the nonlinear least-squares method. As a result, the life span, distribution volume per body weight, and endogenous platelet level (averages for three patients) were calculated as 6.29 d, 0.137 L kg-1, and 1.40 x 10(4) counts microL-1, respectively. The calculated platelet levels in individual patients were compared with the observed ones during the next transfusions, and the relative and absolute differences between calculated and observed values were 2.0 +/- 15.3% and -0.075 +/- 0.443 x 10(4) counts microL-1 (mean +/- SD, 15 observed points for three patients), respectively. These case studies suggest that the model could be clinically useful for individual platelet transfusion.
本文提出了一个血小板输注后血小板处置的动力学模型。在该模型中，血小板输注和内源性血小板生成导致患者体内血小板数量增加，而每个血小板的寿命和年龄则导致血小板数量减少。该模型从理论上描述了血小板输注后血小板数量随时间的变化过程为一条直线后接一条凹曲线。当血小板寿命无变化时，尽管输注时血小板年龄不同，仍观察到线性模式。将这个具有恒定寿命的模型应用于三名接受血小板输注的患者，并使用非线性最小二乘法通过将观察到的血小板水平与模型进行曲线拟合来计算模型参数。结果，计算出的寿命、每体重分布容积和内源性血小板水平（三名患者的平均值）分别为6.29天、0.137L/kg和1.40×10⁴个/微升。将各个患者计算出的血小板水平与下次输血期间观察到的水平进行比较，计算值与观察值之间的相对差异和绝对差异分别为2.0±15.3%和-0.075±0.443×10⁴个/微升（平均值±标准差，三名患者共15个观察点）。这些案例研究表明，该模型在临床个体血小板输注中可能有用。
